H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding

H05K3/06—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding the conductive material being removed chemically or electrolytically, e.g. by photo-etch process

H05K3/061—Etching masks

B—PERFORMING OPERATIONS; TRANSPORTING

B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR

B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM

B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting

B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material

H05K3/0073—Masks not provided for in groups H05K3/02 - H05K3/46, e.g. for photomechanical production of patterned surfaces

H05K3/0076—Masks not provided for in groups H05K3/02 - H05K3/46, e.g. for photomechanical production of patterned surfaces characterised by the composition of the mask

Abstract

A description is given of a process for making a pattern consisting of an electrically conductive material, which process comprises the following steps:… i) electrodeposition of a film of an organic polymer which contains on average more than one reactive functional group per molecule on an electrically conductive surface,… ii) formation of a predetermined pattern of a thermally curable resist on the electrodeposited film, with predetermined portions of the area of said electrodeposited film remaining uncovered and said thermally curable resist containing on average more than one group per molecule which can be reacted with the reactive groups in the electrodeposited film on heating,… iii) removal of the uncovered areas of the electrodeposited film by treatment with a solvent for said film, in which process a surface is produced which exhibits uncovered conductive material in predetermined portions of the area and which, in other predetermined portions of the area, exhibits conductive material which is covered with the electrodeposited film and the resist, and… iv) heating to complete the adhesion of the resist to the electrically conductive surface through the agency of the portions of the area of the electrodeposited film which is covered with the resist, it being possible to perform steps iii) and iv) in any desired sequence.

In den meisten Fällen reicht es aus, die galvanische Abscheidung einige Minuten lang, in der Regel etwa eine Minute lang, bei einer Spannung von bis zu 200 V durchzuführen. In most cases it is sufficient to electroplating for a few minutes, usually for about a minute to perform at a voltage of up to 200V.

Die Haftung des Polymerfilms kann verbessert werden, wenn die Abscheidung in zwei Stufen erfolgt; The adhesion of the polymer film can be improved if the deposition takes place in two stages;zunächst bei einer niedrigen Spannung und anschliessend bei einer höheren Spannung. initially at a low voltage and then at a higher voltage.

Photohärtbare Zusammensetzungen enthaltend Harze mit Carboxylgruppen und Acrylat-oder Methacrylatgruppen, welche sich als Resists einsetzen lassen, sind in der GB-A-1,474,715 beschrieben. A photo-curable compositions containing resins with carboxyl groups and acrylate or methacrylate, which can be used as a resist, are described in GB-A-1,474,715.

Das vorbestimmte Muster des hitzehärtbaren Resists, der in Schritt ii) photogehärtet wird, kann auch durch direktes Aufbingen des Resists in Form eines vorbestimmten Musters erfolgen, beispielsweise durch Verwendung einer Siebdrucktechnik. The predetermined pattern of heat-curable resist is photo-cured in step ii) can also take place by directly Aufbingen of the resist in the form of a predetermined pattern, for example by using a screen printing technique.

Das Lösungsmittel kann so gewählt werden, dass mit dem Entfernen der unbelichteten Flächenanteile der photohärtbaren Resistschicht ebenfalls Schritt iii) des erfindungsgemässen Verfahrens bewirkt wird, dass also die unbedeckten Flächenanteile des galvanisch abgeschiedenen Polymerfilms entfernt werden. The solvent can be selected so that also step iii) is effected of the inventive method with the removal of the unexposed surface portions of the photocurable resist layer, so that the uncovered surface portions of the electro-deposited polymer film to be removed.

[0059] [0059]

Die Ausbildung des vorbestimmten Musters des hitzehärtbaren Resists auf dem galvanisch abgeschiedenen Polymerfilm in Schritt ii) des erfindungsgemässen Verfahrens kann auch durch direktes Aufbingen eines hitzehärtbaren, reaktive Gruppen enthaltenden Resists auf den galvanisch abgeschiedenen Polymerfilm in Form eines vorbestimmten Musters mittels Siebdruck erfolgen. The formation of the predetermined pattern of heat-curable resist on the electrodeposited polymeric film in step ii) of the inventive process can be performed on the electrodeposited polymeric film in the form of a predetermined pattern by screen printing by directly Aufbingen a thermosetting reactive group-containing resists.

[0060] [0060]

In dieser Ausführungsform wird der Resist in der Regel durch Erhitzen gehärtet, bevor die unbedeckten Flächenanteile des galvanisch abgeschiedenen Polymerfllms durch Lösungsmittelbehandlung entfernt werden; In this embodiment, the resist is cured usually by heating before the uncovered surface portions of the electrodeposited Polymerfllms be removed by solvent treatment;hier wird also üblicherweise der oben definierte Schritt iii) nach dem oben definierten Schritt iv) ausgeführt. in this case the above-defined step iii) is usually performed according to the above-defined step iv).

Positiv- oder negativ-arbeitende Photoresists zur Verwendung bei der Herstellung gedruckter Schaltungen sind an sich bekannt und jedes dieser Materialien kann verwendet werden. Positive or negative-working photoresists for use in the production of printed circuits are known per se and each of these materials may be used.Diese Resists können unter wässrigen Bedingungen oder mittels organischer Lösungsmittel entfernt werden. These resists may be removed under aqueous conditions or by means of organic solvents.